Refractory composition and process of making same



ikppiiceticn filed fictober u,

- 7 ii may concern e. Known that I, ARTHUR T, Enquirer-1y, a men oithe United States, ,residinget iilfigars'fslls in the county Niagara and State of New York, have invented certain new endguseiui Improvements in Refractorf/Compositions and Processes of Making Same, of which. tliefollowing ise specificsti'on. V

This inveutionrelates to refractory bricks, blocks or other shaped erticies comprising e framework 013 skeleton of fully shrunk carbon particles, and bond of the ceramic or siiicete 't'ypcl l d y invention comprises also tl'ieicarbo fj ontsining mixture adopted. for the manufacture oi -such shaped-urticles, well a sfor furnace linings he-erths and theiilze Tl e invention also comprises the process by vwliich such articles, linings or the like ere-prepared.

Cerhon-siliczite mixtureslieve been used or proposed forps'ein the manufacture of refractories, huts heretofore compounded tl1ey'lio1ie;11o" 'to po' ssess the properrequisite u h e \TInQly high temperaare employer. 1 have discovered that he 'oper c ic-rtioning or the compoilie caroon component shrui and I griuied described below; it is (11D tiiese meteriois a "in e very high del d heat-resisting site -50: a .l

ta A

retro J I invention new be described by relics to e lcrre dembodiment there- 0 heing'fully undrstoodthet the invenis notre's'tricted to the employment of portion ilr grade or. kind 0". carbonaceous n12 erieh or of ceramic boiul,'inesmuch the principles involved in the "preparations-11d compounding v of the mix- 'obc l roedlynovel. ollows";

l1 Quasi iemineted Jzru the same. The cnlcinetiou is preferz ply r rie out on eiectric ceicining furnace heating being continued until the particles are fully shrunk, in order that they may constitute the or skeleton of a, nonshrinking and. permanent structure, as ivsoriioeci below. 1 here found satisfactory sueciiication of Lettersla'teut.

isle.

I ing, .12"

(through .16" upon .08" aperture). It will NEW Your; esslsu'oie T0 NMIQKAIL misses COEZPANY, mo, .51 cues CQIEEGEITIQN A131) lPPbCES-S, O}? MAKI G July 2%, 192%,

Serial No.

for this purpose to conduct the colcinsuon in such manner as to increase the real density of a coal from about 1.55 to approximately 2.00; or, otherwise expressed; 1 colciue the coal to the maximum"temperature Whicii can be used without nuitcrialiywlis integrating or disrupting the particles or re ducing their crushing" strength; v

F or o sizu'idzird 9orick'or other article having dimensions or thiclcncssioi wall of This is done in order that thevoldsbetween the particles may be determined with sufiicient accuracy and may be of's'uch order oi inagnitudo as hipermiiythe proper proing of the components of the mix- Iit is necessar inerefor 'd the 1 ture with the carbon particles of mel'crial proportions of cerium fines which u'ouid partiali hill the voids in approzzi i2 and couv nient rule for the size perricieshest suited for an article gireu sinister of the particle in proportion to the increase in the dimensions of the article: thus for example for a furnace lining 4c" in thickness or less, particles having an everdiameter of .03 may be used (through upon .02 aperture); for unS lining .06 particles would be preferred (through .08 upon 1A aperture) and for a 12' linparticles would be selected be understood, ho verer, that the selection of ihese purticuizir sizes is not essentiui to the ,iensious is to increase the average Eliprovide voids having the d voii,

1 carbon particles v for the particular use, I then determine the :voids, which may readily be done by noting the volume of liquid required to fill the interstitial spaces of a given volumeof the selected particles. For tully shrunk particles having the dimensions above mentioned, this interstitial volume will be found to be about of the total volume occupied by the particles, with Vallflilflil of perhaps On the basis of. the above data l prepare the refractory composition as follows I take a known volume of the selected carbon particles and mix thoroughly that volume of clay or other bond of the cerannctype which is necessary for completely filling the voids between the carbon particles. To this mixture 1 add suflicient Water to moisten the mass and convert it into a plastic body or heavy caste. After thorou 'h .iu 'in of u i v {3 C3D 'the heavy paste it is ready for use. is

7 clay.

extruded under heavy pressure or otherwise shaped into the desired articles; or tamped into place as furnace lining as the case may be. After prelin'iinarily drying,- the resulting article is'iired at a temperature of about 1000 (l, the effect being to dehydrate the clay and to convert it into a strong bond.

carbon particles in their properposition.

This position is one in which the carbon particles are in mutual contact, as is obv ous from the fact that the total volume of carbon particles used for a given article is suflicient to fill completely the mold in which the article is made. 1 he article comprises therefore a frame-Work or skeleton of fully shrunk, 'aded carbon particles in mutual contact, in intimate admixture with a co ramicbonding material piOPOTlLlOHBd subs..,antiailyto fill. the interstitial spaces or voidshetwcen the particles. As stated abovethe volume-ratios required to give the proper mixture are, approximately, 5,3 parts of graded carbon particles ted"? parts of finely ground clay. The corresponding Weight'rutios are ZLPQl'OXlIDHtGlY, 56 parts of graded carbon particles The article prepared as above and fired to around 1000" possesses distinct electrical conductivity; ivhich may vary somewhat with the kind of carbon used, but is usually of the order of .041; ohm per CM, specific of the average diameter suitable to parts of line incense resistivity. It is mechanically strong, does not shrink or crack on exposure to very high furnace temperatures, and is refractoryat temperatures which are quickly destructive to fire clay.

Owing to the manncrin which the components of the composition are proportioned.

to each other; it is possible to heat the prodnot Without deformation to a temperature range much higher than that required for dehydrating the bond, and this may be done with advantage both as regards strength and refractory properties. For instance the ar-.

ticle may be heated to a temperature at which incipient vitrification of the bond, or

even complete vitrification occurs. which for a good fire clay will be in .the'n'eighborhood "of 14()0 C. At still higher temperatures,

attainable in the'electricfurnace, the silica component-of the clay undergoes reduction with formation of amorphous silicon carbid.

The product thus prepared isparticularly desirable for crucibles. My invention in -l11ClGS the product irrespectiveof the. temperature to which it isheatedprior'to use: I

in this connection it will of cours'ebe understood-that the article fired to 1000" may under certain conditions of use undergo in' to the state] place a further transformation at WhlCll silicon carbid 1s present. This afl'ordsan indication of the extremely re-- fractory character of the article.

I claim: l. A refractory composition comprising fully shrunk, graded carbon particles in mfu tual contact, and a ceramic. bonding material proportioned substantially to fill the interstitial spaces.

2. Process of comprising preparing a mixturezcontainin fully shrunk, graded carbon particles in mu- .tual contact, and a ceramicbonding material proportioned substantially to fill'the interstitial spaces,; forming the article from making a refractoryarticle said l'nix'ture, and firing the same to a tempcrature sulficient to develop the strength of the ceramic bond.

3. Process of making a refractory articlecomprising preparing a mixture containing fully shrunk graded carbon particles mutual contact, and a ceramicbonding material proportioned substantially to fill the interstitial' spaces,. forming the article from said mixture, an'd firing the same to a temthe mixture into silicon carbid.

* In testimony whereof, I aflix my signature.

' ARTHU r- NQK perature sufficient to develop the, strength of the ceramic bond and. to convert portions of 

